Cover plate for hemacytometers



Jan. 1, 1935. c, A, HAUSSER. ET AL COvER PLATE FOR HIEMACYTOMETERS Filed Oct. 14, 1935 Patented Jan. 1, 1935 g V g 3 r UNITED *JST AT:

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' Carl Adolph; and Anthony Adolph v fna ss e rhi adelphi ra. iet 4 b 1 93 .-s ia1 Neas.scii i -3 4 Claims. .(or;

Our invention relates to the transparent cover part the advantages of our invention, the ocplates constituting an element of haemacytometagonal form herein disclosed is considered the ters and like devices, and the principal object most desirable by reason of the fact that it is of the invention is to provide a cover plate of a form readily produced and one which com- 5 generally improved characteristics. bines a maximum stability of support for the 5 A more specific object of the invention is to cover plate with a minimum of contact area reduce the possibility of faulty contact between between the plate and the body of the haemacythe cover plate and the cover plate supports by tometer. reducing the area of mutual contact to a prac- A cover plate made in accordance with our in- 1 tical minimum.- vention possesses several material advantages Another object of the invention is to reduce over the prior cover plate of rectangular form. the possibility of fiow of liquid from the liquid It will be noted by reference to Fig. 3 for exchamber to the cover plate supports by surface ample that the rectangular cover plate, shown tension at the edges of the plate. in broken lines, presents a continuous straight Still another object of the invention is to edge extending betweenthe supports 2 and 3 15 provide. a cover plate that shall be less fragile and the counting chamber 6. In charging thethan the plates previously employed. counting chambers with the liquid, it is a fre- A stillfurther object of the invention is to quent experience to have the liquid flow by provide a cover plate which shall be more surface tension along this straight edgejof the likely to be'within the required wave length accover plate to the cover plate supports 2. and 20 curacy than the cover plates previously used. 3. It will be apparent that a cover plate made In the attached drawing: in accordance with our. invention lacks this;

Figure 1 is a view in perspective of a hmmacystraight edge extending from the counting chamtometer equipped with a cover plate made .in berto either of the supports 2 or 3. The edge accordance with our invention; I f of the cover plate which overlies the counting 5 r Fig. 2 is a view in perspective 'of'the cover chamber terminates in each instance over the plate; moats '7 and 8, andthe angular junction be- Fig.3 is an enlarged plan view of .thehaemacytween this edge and the adjoining diagonal tometer with the cover plate in position thereedges which extend to the supports 2 and 3 is,

on, and sufficient to prevent flow of liquid by surface 30 Fig. 4 is a section on the line 4-4;, Fig. 3. tension between the counting chamber and the' With reference to the drawing; 1 is ,-a haamacysaid cover plate supports.

tometer having the usual spaced cover plate Another highly desirable characteristic of our supports 2 and 3 and the intermediatetable 4. cover'plate resides in reduction in the chance the surface of which is. slightly lower than the of faulty contact between the cover plate and the surfaces of the supports 2 and 3, so that when cover plate supports, this by reason of the matethe cover plate 5 is placed upon said supports rial reduction in the area of contact. between they form with the surface of the table 4 the these elements. From the illustration of Fig. 3,

narrow space 6 which constitutes the counting it will be apparent that the reduction in contact 40 chamber. Moats 7 and 8 separate the supports area between the cover plate and the cover plate 40 2 and 3 from the table 4, and moats 9 and supports is approximately 50%. This reduction 10 are also formed in the body of the hze'mncyin contact area between the cover plate and its tometer outwardly of the supports 2 and 3. supports also materially reduces the chance of Heretofore it has been customary t produce the cover plate failing to be within the required the v r p at s 5 in r tan m, as illuswave length accuracy, since a curvature sufficient 45 trated by broken lines in Fig. 3. We have disto render the cover glass inaccurate might well covered that a material improvement in the lie within the areas that have been eliminated characteristics of the cover plate may be realized by the octagonal design. by forming th pla e i Oc ag form, 88 illllS- A further advantage of our design resides in trated, the dimensions of the Sides of the cover the fact that the cover glass so formed is less 50 plate being such that the e d d es which adfragile than the prior glasses by reason of i the join the long sides of the haemacytometer terreduced area. minate, when the plate'is in normal operatin Itwill be apparent that there may be some position, over the moats 7 and 8. While many modification in the form of the cover plate withother forms might be used to afford at least in out departure from the invention. 55

to overlie the table, the edges of said plate extending across the table terminating both-ends at points overlying the said moatsand the edges of the plate adjoining the" edges first named forming with the latter obtuse angles.

3. A cover plate for hffiatcytofrieters 6f thetype comprising a counting chamber table and 1 cover plate support surfaces separated by meats from said table, said cover plate being formed with edges adapted in assembly to extend transversely across said table, and said edges terminating at points above said moats and forming substantial angles with the adjoining edges of the cover plate.

4. A cover plate for haemacytometers of the type comprising a counting chamber table and cover plate support surfaces separated by meats frf'o'r'n. said tab1e, said cover-infant thawing end edges adapted in assembly to extend transversely across said table and to terminate at points above said moats, and side edges boundirig those portions of the cover plate adapted to engage thesupport surfaces, and edges connedt'irigith said' side edges with the terminal ends oi the end edges and forming obtuse angles Withthe latter;-

CARL ADOLPH HAUSSER.

ANTHONY A. HAUSSER. 

